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Oil change, do you know if your car service shop drains or extracts oil from the top ?


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Posted

hello,

 

I was old fashioned and was thinking that draining oil from the bottom was always better.

After reading about it, it seems that there is no difference and that it is a legend. I also guess that most people don't know that their car service place extracts ? vacuums oil and does not drain. It is done this way since dozens years.

 

Has anybody bought a pneumatic or electric oil extractor in Thailand ? And are you changing oil yourself ?

https://www.lazada.co.th/products/9l-vacuum-oil-fluid-extractor-engine-motorbike-car-oil-suction-pump-transfer-i221815206-s338506268.html

PetHot 7L Manual Vacuum Oil Pump Fluid Extractor Vacuum Oil Transfer of Car Diesel Fuel Litre Tank

 

What do you think ?

thank you.

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Posted
7 hours ago, transam said:

Should always drain from the bottom to remove crud and metal, plus the drain plug can be a good warning sign tool....

 

 

After reading a lot, I am sure that it is the old fashioned way proven useless on most new cars.

 

 

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Posted
Just now, rech said:

 

 

After reading a lot, I am sure that it is the old fashioned way proven useless on most new cars.

 

 

Really, why is that..?

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Posted
On 1/16/2020 at 5:13 PM, Coremouse said:

I think of course shops would drain from bottom? Can't imagine any shop worker would waste precious man-hour to slowly extract oil from a dipstick hole... Plus most japanese cars in Thailand have to be jacked up change oil filter anyway, and plus certain beemers start trending to eliminate engine dipstick... 

 

The extractor could be very handy deal with excessive oil

 

I change oil myself, and I alway use a little bit fresh oil to "flush" the sump, can't do that with extractor

 

 

Sorry but it's clearly faster and easier for any mechanic to do it through dipstick hole....

 

 

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Posted

If I took my car for a oil change I would feel 'better' if they sucked it up.  If not I would worry that they did not tighten the drain plug properly ...  If I was doing it myself I would drain - not waste money on a 'gadget' I would not need .. (I have enough of them already) . ???? .

 

 

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Posted
49 minutes ago, KeeTua said:

I've never owned a car that's had a magnetic drain plug for the engine. It would be unnecessary since your oil filter will remove most particles as the engine oil circulates.

 

If there is gunk in the oil pan that is too heavy to mix with the oil when then engine is running then it is unlikely to flow out the drain hole during an oil change. One reason you're supposed to bring your engine up to running temperature maybe 10 minutes before changing the oil is so any sediment that settled out while parked will mix with the oil prior to draining. If you only drain your engine oil when the engine is cold then over time you will likely build up sludge faster than if you drain from a warmed up engine.

 

On the other hand manual gear boxes, transfer cases and differentials  usually have magnetic drain plugs maybe for a couple of reasons. No oil filters and more likely to have chunks of metal from gears grinding together.

 

 

Wrong

 

49 minutes ago, KeeTua said:

I've never owned a car that's had a magnetic drain plug for the engine. It would be unnecessary since your oil filter will remove most particles as the engine oil circulates.

 

If there is gunk in the oil pan that is too heavy to mix with the oil when then engine is running then it is unlikely to flow out the drain hole during an oil change. One reason you're supposed to bring your engine up to running temperature maybe 10 minutes before changing the oil is so any sediment that settled out while parked will mix with the oil prior to draining. If you only drain your engine oil when the engine is cold then over time you will likely build up sludge faster than if you drain from a warmed up engine.

 

On the other hand manual gear boxes, transfer cases and differentials  usually have magnetic drain plugs maybe for a couple of reasons. No oil filters and more likely to have chunks of metal from gears grinding together.

 

 

So why do they actually make drain plugs with a magnet...?

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Posted
54 minutes ago, transam said:

Wrong

So why do they actually make drain plugs with a magnet...?

Google it. You'll find many discussions about it. The magnetic engine oil drain plugs tend to be aftermarket. Probably your basic weekend mechanic who doesn't really know the difference between a camshaft and a crankshaft buy into the idea that it makes sense to have a magnet.

 

About the only argument I've seen in support of the magnet that makes a little bit of sense is to use it as an early indication that something nasty might be taking place inside the engine if you see chunks of metal on the plug. But that argument doesn't work for me. I prefer to remain blissfully unaware until my ears or my gut tell me there's something wrong.

 

And if someone else is doing the oil change, a Thai shop for example, do you really believe they will take the time to show you your oil plug if they did see extra material on it?

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Posted
44 minutes ago, transam said:

 

Cr_p that maybe floating around in your engine may not all go through the filter, in fact any minute bit of metal may stuff the oil pump before it gets to the filter. The mag plug could save a lot of hassle if it catches a bit of metal. So metal caught does not always me a pending catastrophe, If you have a performance fun ride the mag drain plug can be a good tool to see what's going on, I also used a Oberg screen filter on my fun ride so I knew exactly what was going on in a few minutes that was not magnetic....

Yeah it could be a useful tool especially for a special car or maybe a custom engine that sees high RPMs frequently and you change your oil yourself. But for the typical driver and average car not necessary.

 

If you did see bit more than the usual amount of material on the plug what can you do? Take the car to the shop and have them tear the engine down because there might be a problem? Like I said I'd rather be blissfully unaware instead of worrying over something that probably is not even a real problem.

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Posted
On 1/16/2020 at 6:15 PM, Surelynot said:

Drain surely. All the gunk you need to remove is in the sump plus the oil plug is magnetic and picks up shards of metal.

If you have gunk in the sump you have more problems than you can fix with an oil drain. Additionally, draining oil from the bottom also means the tech had to wait at least 30 minutes to make sure the dirt really makes it down and out of the engine.

Changing motor oil by sucking oil out of the top of the engine will yield just as much dirt removal - to keep dirt in suspension, run the engine until the oil is warm (not hot) then extract the oil immediately, it works like a charm. In most modern engines, the oil filter is also mounted on the top, making a LOF change quick, simple and clean. Conversely, if the filter is mounted at the bottom the old fashioned way, and the car has to be lifted anyway, draining the oil is probably the designed way - just don't forget to change the crush washer to makes sure the drain plug doesn't leak.

 

 

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Posted

those extractors don't drain all the oil. it will show on the dip stick that it has but the dip stick doesn't go all the way to the bottom of the sump it is only a gauge to show when full.

 

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Posted

Ive sat there and watched them lift the car on a hoist and drain via the sump plug.

 

It annoys me they don't put a new washer/seal on the sump plug.

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Posted

You could take this to another level - Buy an oil filter splitter - Then after the oil change - Split the filter open and try to make sence of the various particles that you find inside .. Different metal particles will come from different parts of the engine ... Can give you an indication of what part is deterioration inside the engine ... Often done on aircraft engines (light aircraft). ????

 

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Posted
4 minutes ago, rvaviator said:

You could take this to another level - Buy an oil filter splitter - Then after the oil change - Split the filter open and try to make sence of the various particles that you find inside .. Different metal particles will come from different parts of the engine ... Can give you an indication of what part is deterioration inside the engine ... Often done on aircraft engines (light aircraft). ????

 

Far easier to grab a sample and send it off for analysis.

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Posted

My Isuzu dealer drains the oil and flushes which is the only way to change oil on a diesel. When I used to do it myself I always removed the sump to clean it and the magnetic plug always collected a lot of shards.

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Posted
1 minute ago, chilly07 said:

My Isuzu dealer drains the oil and flushes which is the only way to change oil on a diesel. When I used to do it myself I always removed the sump to clean it and the magnetic plug always collected a lot of shards.

Removing the sump is abit extreme, did you have to drop the crossmember to do it ?

Posted
On 1/18/2020 at 12:10 PM, CharlieH said:

Take my cars to main dealers for many many years, and even here in Thailand its on the lift, up, and drain from the bottom.

How do I know, because they have a huge window where you can sit and observe everything that is done.

 

The other point, if you suck it out, you may (in many cases) have to raise the car to extract the oil filter, so if it has to go up anyway, you might as well drain it.????

So, more efficient and less time consuming to raise, drain, and change the filter.(IMHO) Also a good chance to inspect the underside of the vehicle etc.

 

You must drive a cheap old car.

All Benz dealers extract oil when it's possible and oil filter is on top.

 

 

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